Henning Pangels

The Demeter System for Automated Harvesting

Automation of agricultural harvesting equipment in the near term appears both economically viable and technically feasible. This paper describes the Demeter system for automated harvesting. Demeter is a computer-controlled speedrowing machine, equipped with a pair of video cameras and a global positioning sensor for navigation. Demeter is capable of planning harvesting operations for an entire field, and then executing its plan by cutting crop rows, turning to cut successive rows, repositioning itself in the field, and detecting unexpected obstacles. In August of 1997, the Demeter system autonomously harvested 40 hectares (100 acres) of crop in a continuous run (excluding stops for refueling). During 1998, the Demeter system harvested in excess of 48.5 hectares (120 acres) of crop, cutting in a variety of fields.

Behavior-based gait execution for the Dante II walking robot

The Dante project is developing walking robots to explore inside volcanic craters. These robots face many challenges including generating a walking gait in rough, obstacle-filled terrain. For the walking robot Dante II, we implemented a gait controller to address this situation. Our approach is embodied in a network of asynchronous processes that establish a fundamental gait cycle while maintaining body posture, and reacting to bumps and slips. We describe our implementation, and its relation to similar behavioral approaches, and discuss Dante IIs performance during testing and on its descent into Mount Spurr.

Operator Interfaces and Network-Based Participation for Dante II

Dante II, an eight-legged walking robot developed by the Dante project, explored the active volcanic crater of Mount Spurr in July 1994. In this paper, we describe the operator interfaces and the network-based participation methods used during the Dante II mission. Both virtual environment and multi-modal operator interfaces provided mission support for supervised control of Dante II. Network-based participation methods including message communications, satellite transmission, and a WorldWideWeb server enabled remote science and public interaction. We believe that these human-machine interfaces represent a significant advance in robotic technologies for exploration.

Progress towards robotic exploration of extreme terrain

A high degree of mobility, reliability, and efficiency are needed for autonomous exploration of extreme terrain. These requirements have guided the development of the Ambler, a six-legged robot designed for planetary exploration. To address issues of efficiency and mobility, the Ambler is configured with a stacked arrangement of orthogonal legs and exhibits a unique circulating gait, where trailing legs recover directly from rear to front. The Ambler is designed to stably traverse a 30 degree slope while crossing meter sized features. The same three principles have provided many constraints on the design of a software system that autonomously navigates the Ambler through natural terrain using 3-D perception and a combined deliberative/reactive architecture. The software system has required research advances in real-time control, perception of rugged terrain, motion planning, task-level control, and system integration. This paper presents many of the factors that influenced the design of the Ambler and its software system. In particular, important assumptions regarding the mechanism, perception, planning, and control are presented and evaluated in light of experimental and theoretical research of this project.